<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">I have 3 web servers, and although they at one time all showed up successfully, now one of them does not.<div><br></div><div>i have verified on the web server in question that nrpe is running and listening on tcp/5666:</div><div><br></div><div><div><b>netstat -ntlp | grep nrpe</b></div><div><b>tcp 0 0 0.0.0.0:5666 0.0.0.0:* LISTEN 13920/nrpe</b></div></div><div><b><br></b></div><div><div><b>/etc/init.d/nrpe status</b></div><div><b>nrpe (pid 13920) is running...</b></div></div><div><br></div><div>I've checked the nrpe.cfg on another server that is showing up, and compared b/t the two, and they look identical.</div><div><br></div><div>i've got an IPTables rule that allows connections on the web server:</div><div><br></div><div><b>-A RH-Firewall-1-INPUT -p tcp -m tcp --dport 5666 -j ACCEPT</b></div><div><br></div><div>One of the things that doesn't test right though is the <i>check_nrpe</i> command:</div><div><br></div><div><div> <b>/usr/lib64/nagios/plugins/check_nrpe -H localhost -c check_load</b></div><div><b>NRPE: Unable to read output</b></div></div><div><br></div><div>but tail /var/log/messages gives me something interesting, perhaps?</div><div><br></div><div><div><b>Sep 21 13:30:08 mywebserver kernel: Removing netfilter NETLINK layer.</b></div><div><b>Sep 21 13:30:09 mywebserver kernel: ip_tables: (C) 2000-2006 Netfilter Core Team</b></div><div><b>Sep 21 13:30:10 mywebserver kernel: Netfilter messages via NETLINK v0.30.</b></div><div><b>Sep 21 13:30:10 mywebserver kernel: ip_conntrack version 2.4 (8192 buckets, 65536 max) - 304 bytes per conntrack</b></div></div><div><b><br></b></div><div>On the nagios server, i've checked the mywebserver.cfg file and it looks legit and cross-compared with the two others, it seems identical (except for IP of course):</div><div><br></div><div><div><b># Host definition</b></div><div><b># Modified 81610</b></div><div><b><br></b></div><div><b>define host{</b></div><div><span class="Apple-tab-span" style="white-space:pre"><b> </b></span><b>use linux-server ; Inherit default values from a template</b></div><div><b> host_name mywebserver ; The name we're giving to this server</b></div><div><b> alias mywebserver ; A longer name for the server</b></div><div><b> address 10.0.100.139 ; IP address of the server</b></div><div><b>}</b></div><div><b><br></b></div><div><b>define service{</b></div><div><b> use generic-service</b></div><div><b> host_name mywebserver</b></div><div><b> service_description Home Page</b></div><div><b> check_command check_http!ww2</b></div><div><b>}</b></div></div><div><br></div><div> </div><div><br></div><div>Any feedback, suggestions, thoughts, etc.. is much appreciated in advance</div><div><br></div><div>JW</div></body></html>